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Jet-induced supernovae (SNe) have been suggested to take place in gamma-ray bursts (GRBs) and highly-energetic SNe (hypernovae). I summarize hydrodynamical and nucleosynthetic properties of the jet-induced explosion of a population (Pop) III 40 M⊙ star. In particular, I present the aspherical effect on nucleosynthetic yield and its dependence on properties of the relativistic jets. Nucleosynthesis in Pop III SNe can be constrained by abundance patterns of extremely metal-poor (EMP) stars which were formed in the early universe. The jet-induced SNe acquire favorable features for EMP stars as follows: (1) the ejection of Fe-peak products and the fallback of unprocessed materials are compatibly realized and (2) the varieties of energy deposition rates in the jet-induced SNe explains a trend of [C/Fe] in the EMP stars. Furthermore, the variation of energy deposition rates lead the variation of ejected 56Ni(Fe) masses, and thus can explain both GRB-associated SNe and GRBs without bright SNe, GRBs 060505 and 060614. Therefore, I propose the analogical origins of GRBs and EMP stars and their connection. [ABSTRACT FROM AUTHOR]

The calculations for the evolution of dust within Population III supernova remnants (SNRs) are presented, based on the models of dust formed in the unmixed ejecta of Type II SNe. We show that once dust grains collide with the reverse shock penetrating into the ejecta, their fates strongly depend on the initial radius aini. For SNRs expanding into the interstellar medium (ISM) with nH,0 = 1 cm-3, grains of aini<0.05 μm are trapped in the hot gas to be completely destroyed; grains of aini = 0.05–0.2 μm are piled up in the dense shell formed behind the forward shock; grains of aini>0.2 μm are injected into the ISM without being eroded significantly. The total mass of surviving dust is 0.01 to 0.8 M⊙ for nH,0 = 10 to 0.1 cm-3. We also investigate the influence of the piled-up dust on the elemental abundances of the second-generation stars formed in the dense shell of Population III SNRs. The comparison of the calculated elemental abundances with those observed in hyper-metal-poor (HMP) and ultra-metal-poor (UMP) stars indicates that the transport of dust separated from metal-rich gas can be an important process in determining the abundance patterns of Mg and Si in HMP and UMP stars. [ABSTRACT FROM AUTHOR]

The first chemical enrichment has been made by supernovae (SNe) of metal-free Population (Pop) III stars. The first generation stars formed from the primeval density fluctuation are called Pop III.1 stars and predicted to be as massive as > 300M⊙. Although such very massive stars (VMSs) had been considered to directly collapse to black holes, the VMSs are recently suggested to be able to explode as gamma-ray bursts (GRBs). In order to clarify whether the VMSs can contribute to the chemical enrichment in the early universe, we present explosive nucleosynthesis in VMS explosions and compare the abundance patterns of their yields with those of the extremely metal-poor (EMP) stars. It is shown that the yields of VMS explosions with explosion energy of 6.3 × 1054 erg cannot reproduce [C/Fe], [Mg/Fe], and [Zn/Fe] simultaneously. This implies that the VMSs are likely not to dominantly contribute to the chemical enrichment in the early universe. [ABSTRACT FROM AUTHOR]

We describe the evolution of dust within Population III supernova remnants (SNRs) and investigate the chemical compositions of the dust piled up in their dense shells. We show that the resulting abundance patterns of the major elements in the dense shells are in good agreement with that observed for a Galactic halo star, SDSS J102915+172927. This allows us to propose that SDSS J102915+172927 might be the second-generation star formed in the dust-enriched dense shell of a Population III SNR. We conclude that the segregation of dust from the metal-rich ejecta gas can be an important process in determining the abundance patterns of primitive low-mass stars. [ABSTRACT FROM AUTHOR]

A long GRB is thought to occur when a massive star ends its life and thus it is expected to be accompanied by a type Ic supernova (SN) which also results from a massive star. Several nearby long GRBs are observed with type Ic SNe. However, some nearby long GRBs are observed without SNe, even though they are close enough to be able to observe the accompanied SNe (e.g., GRB060614). Within our current picture of long GRBs, long GRBs should be accompanied by SNe and these long GRBs without SNe are one of the challenges for the current theory of long GRBs. One possible reason is that the accompanied SNe were so faint that we just missed them. For example, SN 2008ha was only as bright as ∼-14 mag in the R band at maximum brightness. The explosion energy, ejecta mass, and 56Ni mass of SN 2008ha are estimated as about 1048 erg, 0.1 M⊙, and 0.003 M⊙, respectively. If such a SN is accompanied by long GRBs, we might miss it. We performed numerical calculations of hydrodynamics and radiation transport and confirmed that SN 2008ha could have been a type Ic supernova and originated from a core-collapse SN with a significant amount of fallback. This demonstrates that some type Ic SNe like SN 2008ha could be very faint because of fallback. Our results suggest that long GRBs without SNe could have been accompanied by such faint SNe with fallback and we could have just missed the accompanied SNe and the current picture of long GRBs would be consistent with long GRBs without SNe. [ABSTRACT FROM AUTHOR]

The influence of a large variation of Ye on explosive yield is investigated. We calculate nucleosynthesis with the initial electron fraction Ye ranging from 0.48 to 0.58 in explosive Si burning region in Population III, 25 M⊙ supernovae. We obtain the significant overproduction of odd elements, K and Sc. In the Ye < 0.5 cases light p-process nuclei are enhanced. We find that the abundance pattern taken from arbitrary mixture of each nucleosynthesis yield in various values of Ye can reasonably explain that in observed extremely metal-poor stars. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]